Photos: 'Big Bang Theory' cast

Season 7 of the very popular comedy "The Big Bang Theory" had its finale on May 15. Johnny Galecki and the Kaley Cuoco play Leonard and Penny who just got engaged on the series. Here is a primer on the show's characters:

Season 7 of the very popular comedy "The Big Bang Theory" had its finale on May 15. Johnny Galecki and the Kaley Cuoco play Leonard and Penny who just got engaged on the series. Here is a primer on the show's characters: